Method and device for keeping outfall drainage in service during sewerage construction

Abstract

In a method for keeping outfall drainage in service whilst constructing sewerage, wherein a main drain is laid in the position of an old drain or in a new line by pipe or shield tunnelling under closed or semi-open construction using a working pipe or shield (1) at the tunnelling end (9), at essentially the same time as the working pipe or shield (1) is tunnelling, at least one outfall drain (30) is laid below ground through at least one working orifice (20) in the working pipe or shield (1), so that the outfall drain (30) lies alongside the main drain. A device suitable for implementing the method has a working pipe or a shield (1) with at least one working orifice (20) for laying at least one underground outfall drain (30) alongside the main drain from the interior of the working pipe or shield (1).

We claim: 
     
       1. Method for keeping outfall drainage in service while constructing sewerage, wherein a main drain is laid in the position of an old drain or in a new line by pipe or shield tunnelling under closed or semi-open construction using a working pipe or shield (1) at the tunnelling end, wherein at essentially the same time as the working pipe or shield (1) is tunnelling, laying at least one outfall drain (30, 30') below ground through at least one working orifice (21, 22, 21', 22') in the working pipe or shield (1), so that the outfall drain (30, 30') lies alongside the main drain. 
     
     
       2. Method according to claim 1, wherein and the cavity required for the outfall drain (30, 30') is formed in the ground while the working pipe or shield (1) is tunnelling by means of a lateral protrusion (24, 24') on the working pipe or shield (1). 
     
     
       3. Method according to claim 2, wherein the outfall drain (30) is laid through a laying orifice (21) provided in the side wall (14) of the working pipe or shield (1), which is surrounded on the outside by a protective casing (24), which is closed in the tunnelling direction and is open in the direction opposite the tunnelling direction and which produces the cavity required in the ground for the outfall drain (30) as the working pipe or shield (1) tunnels forwards. 
     
     
       4. Method according to claim 1, wherein on reaching an existing feeder pipe (36), the feeder pipe (36) is severed from its current mouth and connected via a branch element (38) to the stretch of outfall drain (30) already laid, wherein at least some of the work required for this purpose is carried out from the interior of the working pipe or shield (1) through the working orifice (20). 
     
     
       5. Method according to claim 4, wherein the feeder pipe (36) is temporarily sealed for a time. 
     
     
       6. Method according to claim 1, wherein the outfall drain (30) is made up of essentially rigid pipe lengths (32) and is laid by adding the pipe length to be laid (34), with its front end pointing in the direction of tunnelling, through the working orifice (20) with its rear end against the stretch of outfall drain (30) already laid. 
     
     
       7. Method according to any one of claims 1 to 5, comprising the step of laying the outfall drain as flexible endless piping, bending back the endless pipe to be laid in the interior of the working pipe or shield (1) and feeding the endless pipe, with its free end pointing away from the tunnelling direction, through the working orifice (20) and connecting it onto the stretch of outfall drain (30) already laid. 
     
     
       8. Device for keeping outfall drainage in service while constructing sewerage, with a working pipe or shield (1) wherein a main drain is laid in the position of an old drain or in a new line by pipe or shield tunnelling under closed or semi-open construction using the working pipe or shield (1) at the tunnelling end, characterised in that the working pipe or shield (1) is provided with at least one working orifice (21, 22, 21', 22') for laying at least one underground outfall drain (30, 30') alongside the main drain from the interior of the working pipe or shield (1). 
     
     
       9. Device according to claim 8, wherein the working pipe or shield (1) is provided with a lateral protrusion (24, 24') for producing the cavity in the ground required for the outfall drain (30, 30') as the working pipe or shield (1) is tunnelling. 
     
     
       10. Device according to claim 9, wherein the working orifice (20) has a laying orifice (21) provided in the side wall (14) of the working pipe or shield (1), which is surrounded on the outside by a protective casing (24), which is closed in the tunnelling direction and open in the direction opposite the tunnelling direction and which is arranged in such a way as to produce the cavity in the ground required for the outfall drain (30) as the working pipe or shield (1) is tunnelling. 
     
     
       11. Device according to claim 10, wherein the laying orifice (21) is a slit running in the longitudinal direction of the working pipe or shield (1). 
     
     
       12. Device according to claim 10, wherein the working orifice (20) has a fitting orifice (22) provided in the side wall (14) of the working pipe or shield (1), which is adjacent to the end of the laying orifice (21) that faces away from the tunnelling direction. 
     
     
       13. Device according to claim 12, wherein the fitting orifice (22) can be closed. 
     
     
       14. Device according to claim 13, characterised in that the fitting orifice (22) can be closed by means of a double slide device (28, 29) mounted on the interior wall of the working pipe or shield (1) which can be moved transversely relative to the tunnelling direction. 
     
     
       15. Device according to claim 8, wherein the device has a shield (1), in which, between cutting shoe (2) and machine pipe (4), an essentially pipe-shaped laying device (3) having at least one working orifice (21, 22, 21', 22') is provided, which is movably joined to the cutting shoe (2) and machine pipe (4). 
     
     
       16. Device according to claim 8, wherein several working orifices (20, 20') are provided in the side wall (14) of the working pipe or shield (1) for laying two underground outfall drains (30, 30') on the two sides of the main drain.